Im firmly against these "X minutes to read" estimates because the amount of time it takes to read something is highly dependent on many variables (on both the reader side and article side). I would much rather have a "Short, Medium, Long, Novel" kind of scale which is simply a scaled word count of some kind.
Author here. I don't actually think so. This is likely closer to 40 minutes of reading time, and I personally don't think it is the most difficult writing to read.
Is this actually correct? I am inclined to think not but it is difficult to judge just from scrolling through it quickly.